Typical Water Quality Values

This list is a supplement to the Annual Water Quality report. It is meant to give an estimate of the types of compounds analyzed and the levels at which they are found. If you need specific information please feel free to contact the water quality laboratory at 480-350-8330 or view the annual water quality report. The numbers may vary throughout the year due to varying water sources however, the annual averages are relatively consistent from year to year. Unless otherwise stated, these numbers were taken from data gathered between Jan - Dec 2014.

Many of the following parameters are regulated by the Safe Drinking Water Act of 1974 and the 1986 Amendments. Analyses are preformed as required and the concentrations of the regulated parameters detected in Tempe water are LESS THAN the Maximum Contaminant Levels (MCL's).

Inorganic Chemicals - metals, salts and minerals can be naturally occurring or result of urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining or farming runoff.

* Action Level- if the value of either Lead or Copper values exceed the Action Level additional treatment techniques are required as per the "Lead and Copper Rule".

** SMCL- secondary maximum contaminant level, a number associated with the aesthetic quality of water. According to the EPA these numbers are guidelines not enforceable standards. There are no health problems associated with these compounds.

Results are expressed in mg/l except *NTU= Nephelometric Turbidity Unit (measure of water clarity) maximum monthly average value **MHOS/CM (micromhos per centimeter) units used to measure conductance ***Alkalinity and hardness are reported as mg/l calcium carbonate (CaCO3) ^ Customers are often interested in Hardness expressed in grains per gallon, for settings on dishwashers or water softeners. To calculate grains per gallon, divide the hardness value in mg/l by 17.1 ^^ Coliform MCL, is defined as presence of coliform bacteria in 5% or more of monthly samples. Tempe is required to collect 120 samples/ month for coliform.
ND-not detected.

The VOC program consists of monitoring the distribution system and wells for approximately 40 other compounds which are currently unregulated. For these compounds the Minumum Reporting Levels (MRL's) are listed. The MRL is the lowest limit accurately detected by the instrument.

The SOC program consists of monitoring the distribution system and wells for approximately 30 other compounds which are currently unregulated. For these compounds the Minimum Reporting Levels (MRL's) are listed. The MRL is the lowest limit accurately detected by the instrument.

Unregulated SOC's ~ Drinking Water Values

Analyte

MRL (mg/l)

Average Value (mg/l)

Aldicarb

0.0005

<0.0005

Aldicarb Sulfoxide

0.0005

<0.0005

Aldicarb Sulfone

0.0008

<0.0007

3-Hydroxycarbofuran

0.002

<0.002

Aldrin

0.00005

<0.00005

Propachlor

0.00005

<0.00005

Butachlor

0.00005

<0.00005

Carbaryl

0.002

<0.002

Dicamba

0.00008

0.00008

Dieldrin

0.0002

<0.0002

Methomyl

0.001

<0.001

Metolachlor

0.00005

<0.00005

Metribuzin

0.00005

<0.00005

Trigger Value*

Arocholr 1016

0.00008

<0.00007

Arocholr 1221

0.02

<0.0001

Arocholr 1232

0.0005

<0.0001

Arocholr 1242

0.0003

<0.0001

Arocholr 1248

0.0001

<0.0001

Arocholr 1254

0.0001

<0.0001

Arocholr 1260

0.0002

<0.0001

*If any trigger value is exceeded, then further testing must be performed for Decachlorobiphenyl

* Radium 226 and Radium 228 are not required to be analyzed separately when Gross Alpha is less than 5 pCi/l, it is assumed that their value is also less than 5 pCi/l.
** 50 pCi/l is the approximate equivalent to 4 millirem/year

Unregulated Contaminant Monitoring Rule (UCMR) ~ 2002 DataThese compounds do not currently have Maximum Contaminant Levels the EPA is gathering data to help them establish regulatory limits. For these compounds the Minimum Reporting Levels (MRL) are listed. The MRL is the lowest limit accurately detected by the instrument.(2002 data)

The 12 substances which EPA identified for Tempe to monitor included compounds used in explosives, insecticides, herbicides, gasoline and solid fuel propellant additives. None of these compounds were detected in the drinking water monitoring conducted over a 12 month period.

Analyte

MRL (mg/l)

Average Value is (mg/l)

Perchlorate

0.004

<0.004

2,4-Dinitrotoluene

0.002

<0.002

2,6-Dinitrotoluene

0.002

<0.002

Acetochlor

0.002

<0.002

4,4'-DDE

0.0008

<0.0008

DCPA mono-acid degradate

0.002

<0.001

DCPA di-acid degradate

0.001

<0.001

EPTC

0.001

<0.001

Molinate

0.0009

<0.0009

Terbacil

0.002

<0.002

MTBE

0.005

<0.005

Nitrobenzene

0.01

<0.010

Unregulated Contaminant Monitoring Rule (UCMR2) ~ 2008 DataThese compounds do not currently have Maximum Contaminant Levels the EPA is gathering data to help them establish regulatory limits. For these compounds the Minimum Reporting Levels (MRL) are listed. The MRL is the lowest limit accurately detected by the instrument.(2008 data)

The 25 substances which the EPA identified for Tempe to monitor included compounds reladed to insecticides, herbicides, flame retardants, contaminants used in explosives, and chemical compounds that exist in sources of drinking water or that form when disinfectants are added to water to kill microbes. None of these compounds were detected in the drinking water monitoring which was conducted over a 12 month period.